Posted
by
samzenpus
on Tuesday August 16, 2011 @09:24AM
from the small-world dept.

An anonymous reader writes "Yahoo has partnered with Facebook to test the iconic social experiment known as 'six degrees of separation' (everyone is on average approximately six steps away from any other person on Earth). The goal of the Small World Experiment is to determine the social path length between two strangers by tapping into the world's largest social network and its 750 million users, each of whom have an average of 130 friends." Looks like a fun project, but not quite as useful as knowing how close you are to Kevin Bacon.

It's not a travelling salesman problem, it's a shortest path problem, and as such is much easier. For the distance between two specific people, you'd need the Dijkstra algorithm, and for the distance between any two people, you could use Floyd-Warshall. This one is in O(n^3), where n is the number of users; that's a big number, but it's nowhere near the (supposed) complexity of the TSP.